Insights into the Halogen Oxidative Addition Reaction to Dinuclear Gold(I) Di(NHC) Complexes
| Autor: | Alessandro Dolmella, Lucia Caporaso, Marco Baron, Claudia Graiff, Abdirisak Ahmed Isse, Laura Falivene, Luigi Cavallo, Armando Gennaro, Cristina Tubaro, Marino Basato |
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| Rok vydání: | 2016 |
| Předmět: |
dinuclear complexes
gold mechanistic studies N-heterocyclic carbenes oxidative addition Chemistry (all) 010405 organic chemistry Stereochemistry Chemistry Organic Chemistry Large series General Chemistry 010402 general chemistry 01 natural sciences Medicinal chemistry Oxidative addition Catalysis 0104 chemical sciences Halogen Molecule Reactivity (chemistry) |
| Zdroj: | Chemistry (Weinheim an der Bergstrasse, Germany). 22(29) |
| ISSN: | 1521-3765 |
| Popis: | Gold(I) dicarbene complexes [Au2 (MeIm-Y-ImMe)2 ](PF6 )2 (Y=CH2 (1), (CH2 )2 (2), (CH2 )4 (4), MeIm=1-methylimidazol-2-ylidene) react with iodine to give the mixed-valence complex [Au(MeIm-CH2 -ImMe)2 AuI2 ](PF6 )2 (1 a(I) ) and the gold(III) complexes [Au2 I4 (MeIm-Y-ImMe)2 ](PF6 )2 (2 c(I) and 4 c(I) ). Reaction of complexes 1 and 2 with an excess of ICl allows the isolation of the tetrachloro gold(III) complexes [Au2 Cl4 (MeIm-CH2 -ImMe)2 ](PF6 )2 (1 c(Cl) ) and [Au2 Cl4 (MeIm-(CH2 )2 -ImMe)2 ](Cl)2 (2 c(Cl) -Cl) (as main product); remarkably in the case of complex 2, the X-ray molecular structure of the crystals also shows the presence of I-Au-Cl mixed-sphere coordination. The same type of coordination has been observed in the main product of the reaction of complexes 3 or 4 with ICl. The study of the reactivity towards the oxidative addition of halogens to a large series of dinuclear bis(dicarbene) gold(I) complexes has been extended and reviewed. The complexes react with Cl2 , Br2 and I2 to give the successive formation of the mixed-valence gold(I)/gold(III) n a(X) and gold(III) n c(X) (excluding compound 1 c(I) ) complexes. However, complex 3 affords with Cl2 and Br2 the gold(II) complex 3 b(X) [Au2 X2 (MeIm-(CH2 )3 -ImMe)2 ](PF6 )2 (X=Cl, Br), which is the predominant species over compound 3 c(X) even in the presence of free halogen. The observed different relative stabilities of the oxidised complexes of compounds 1 and 3 have also been confirmed by DFT calculations. |
| Databáze: | OpenAIRE |
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